1. Field of the Invention
The present invention relates to a refrigeration apparatus, a method for controlling a refrigeration apparatus, and a computer readable media for controlling a computer.
2. Discussion of the Background
Generally, a refrigeration apparatus is provided with a condensation pressure adjustment valve, a fan controller and the like in a condenser of the refrigeration apparatus. The condensation temperature is controlled around 30° C. at the lowest limit, irrespective of the evaporation temperature of the refrigerant in or the outside temperature of the unit cooler. In this respect, the present inventor has demonstrated that a higher efficiency and significant power savings can be achieved by operating the refrigeration apparatus without controlling the condensation pressure all year around. See “Energy-Saving Freezer and Refrigeration Equipment without Condensation Pressure Control” Refrigeration and Air Conditioning Equipment, Vol. 25, No. 6, pp. 17-25. June 1998. The contents of this reference are incorporated by reference in their entirety.
According to this reference, it is possible to operate the refrigeration apparatus at a very small pressure differential by allowing the condensation temperature to follow the course of outside temperatures without controlling it around 30° C., and by selecting a flow distributor based on the freezer performance and the refrigerant temperature under a low condensation pressure.
More specifically, this involves the selection of nozzle diameter, tube diameter and tube length which will not allow the pressure drop in the nozzles and tubes of the distributor to fall below 70 kPa under the minimum condition for uniform refrigerant distribution in the unit cooler. As a result of this, refrigerant liquid will be uniformly distributed to the various circuits in the unit cooler. By employing this special design and operation approach, it is proven that the operation becomes possible at a very small difference of 300 kPa between the evaporation pressure and the condensation pressure of refrigerant.